Game of Thrones
Moat Cailin
Catelyn Stark and Ser Rodrik arrive at Robb's war camp in episode 1x08 “The Pointy End”.
Lannister War Camp
Jaime meets with Tywin in his tent in episode 1x07 “You Win or You Die”. Tyrion and his mercenaries join Tywin's army after escaping the Vale in episode 1x08 “The Pointy End”.
Robb's Riverlands Camp
Robb introduces his mother to Talisa in episode 2x06 “The Old Gods and the New”. Robb stops a group of his bannermen from killing Jaime in episode 2x07 “A Man Without Honor”.
The Twins
Robb and his bannermen wait to hear back about the conditions for them passing through The Twins in episode 1x09 “Baelor”.